Method and machine for reducing cellulose to fibers and for transforming the same into the liquid state



0. VENTER. v

METHOD AND MACHINE FOR REDUCING CELLULOSE T0 FIBERS AND FOR TRANSFORMINGTHE SAME INTO THE LIQUID STATE.

Patented Apr. 11, 1922.

APPLICATION FILED MAY 20, 1921.

i through the cutting machine.

UNITED STATES PATENT @FFHCE.

OTTO VENTER, F CHEMNITZ, GERMANY.

METHOD AND MACHINE FOR REDUCING CELLULOSE T0 FIBERS AND FOR TRANS-FORMIN'G THE SAME INTO THE LIQUID STATE,

Application filed May 20,

T 0 all whom it may concern:

Be it known that I. Orro "EXTER. a citizen of the German Republic,residing at Chemnitz. Germany. have'invented certain new and usefulImprovements in a Method and Machine for Reducing Cellulose to Fibersand for Transforming the Same. Into the Liquid State, (for which I havefiled aplications in Germany April 27, 1920. and duly 8, 1920,) of whichthe following is a specification.

This invention relates to a special method of reducing cellulose tofibers, to a process for the transformation of the'sulphidized cellulosetreated with caustic soda into the liquid state. specially for theproduction of artificial threads, and to a machine for carrying out themanufacturing method. The cellulose which is usually like cardboard mustbe reduced to small pieces like flakes of oat meal before it can befurther treated.

In order that the invention may be clearly understood. I shall proceedto describe the same with reference to the accompanying drawing, whereinFig. 1 shows by way of example a part of a machine whichcan be used forthe application of the improved manufacturing method.

Figs. 2 and 3 show in front elevation and in side elevationa plant forcarrying through the method in its totality.

The improved manufacturing method consists in making the material. whichhas been previously cut into small pieces. pass continuously through acutting 'and mixing machine so that simultaneously with the reducing tofibers a thorough mixing is effected under pressure. A meat cut-tingmachine of well known construction is well adapted for this purpose. Theworm h of this machine (Fig. 1) effects the feeding of the materialwhich, being pressed against t-he cutting knives 2' and against theperforated disk It is reduced to fibers and compressed at the same time.It is indifferent whether the cutting knives revolve and the disk isstationary or inversely. The cellulose must have, for practical reasons,a sufficiently high degree of moistness and it is therefore saturateduniformly with a sufficient quantity of a caustic soda solution. Inorder to ensure that the reducing to fibers be as finely as necessarythe material is conveyed several times For the first Specification ofLetters Patent. Patented Apr, 11, 19:22

1921. Serial No. {171,220.

passage of the material through the machine a perforated disk ispreferably used which has larger perforations than the disks which areused later on. For every succeeding operation a perforated disk is usedwhich has smaller erforations than the disk used for the previousoperation. From these cutting machines the pulp of materialis fed into aconvenient receptacle.

It is advisable to mount in series several cutting machines so that thematerial gets automatically from one machine into the other so that thedesired degree of fineness can be realized at one passage of thematerial from one end of the set of cutting machines to the other end.It is evident that in this case perforated disks will be used in thedifferent machines with perforations of gradu ally decreasing diameters.The different cutting machines can work at different speed.

The cutting machines can be connected with one another in such a mannerthat the admission of air is excluded. In each of the cutting machinesseveral perforated disks with. perforations of different size can beused.

In order to sulphidize the cellulose saturated with caustic soda(xanthogenate) it is necessary to combine carbon disulphide with thesame which can be done with the aid of a stirring apparatus enclosedpreferably in a closed vessel with outlet for the gases produced. Thissulphidized xanthogenate (sulphoxanthogenate) must be transformed into apulp (aqueous liquid) which is adapted to be used for the production ofartificial threads.

In order to bring the sulphoxanthogenate to the liquid state. thematerial is made to pass repeatedly through a cutting and mixingmachine. e. g. to a machine as shown in Fig. 1. The worm a effects thefeeding of the material so that it is pressed against the cutting knives7) and through the finely perforated disk 0. it being indifferentwhether the knives revolve and the disk is suance of the process themixture has to be treated with water which is effected by conducting themixture again through the cutting machine and by adding water until themixture becomes sufficiently thinly liquid so that it can be treated ina stirring apparatus where more water is added to the mixture. Thestirring apparatus could be omitted and the final addition of watercould be effected when the mixture is conducted again through the mixingapparatus.

\Vhen several mixing machines are mounted the one behind the other theliquids can ,be added successively to the mixture till a dilution hasbeen produced which permits of treating the mixture further in astirring apparatus. or the proper dilution is produced in the mix-ingmachines.

This improved method saves much power and time, so that such a plantworks very cheaply although the output is considerable. The machines canbe stationary or movable.

Figures 2 and 3 of the drawing represent a plant in which the cuttingand mixing machines a (1?, a a? are stepwise mounted in a common frame6, each upper machine being connected with the succeeding lower machineby a conduit 0. The liquefied material flows from the last machine aintoa vat d. A hopper 6 serves for feeding the material to the upper mixingapparatus a For the treatment of the sulphoxanthogenate solution ofcaustic soda is supplied to the mixer a through the pipe 7'. Thematerial fiows from a to a which has a pipe g for the supply of liquid,which in this case consists of water or of a diluted caustic sodasolution, the diluted material flowing then to a and so on. The mixtureis thus properly diluted and thoroughly mixed.

The mixing machines can also be arranged on the same plane. Any wellknown drive can be used.

I claim 1. An improved method for reducing cellulose to fibers speciallydesigned for the production of artificial threads, consisting inconducting the cellulose whiclrhas been previously saturated withcaustic soda repeatedly through a cutting and mixing machine wherein thematerial'when being conveyed is submitted at the same time to a pressingaction.

2. An improved method for reducing cellulose to fibers speciallydesigned for the production of artificial threads. consisting inconducting the cellulose which has been previously saturated withcaustic soda through several cutting and mixing machines mounted the onebehind the other so that the material reduced to fibers flowscontinuously from one machine to the other.

3. An improved method for transforming sulphidized cellulose treatedwith caustic soda into a convenient state of liquidity specially for theproduction of artificial threads, consisting in conducting thesulphoxanthogenate continuously and repeatedly through a cutting andmixing machine of the type used for cutting meat in submitting thematerial to pressure and to compression, in adding to it first adetermined quantity of caustic soda solution and then water incorresponding proportion.

=1. An improved method for transforming sulphidized cellulose treatedwith caustic soda into a convenient state of liquidity specially for theproduction of artificial threads, consisting in conducting-thesulphoxanthogenate continuously and repeatedly through a plant ofcutting and mixing machines of the type used for cutting meat arrangedthe one behind the other so that the mass flows from one machine totheother and in submitting the material to pressure and to compression, inadding to it first a determined quantity of caustic soda solution andthen water in corresponding proportion.

5. An improved machine for reducing to fibers cellulose which has beensaturated with caustic soda (xanthogenate). for sulphidizing the sameand for transforming the sulphoxanthogenate into the liquid statecomprising in combination a number of cutting and mixing machines of thetype of the meat cutting machines and conduits for connecting themachines with one another.

6. An improved machine for reducing to fibers cellulose which has beensaturated with caustic soda (xanthogenate). for sulphidizing the sameand for transforming the sulphoxanthogenate into the liquid statecomprising in combination a number of cutting and mixing machines of thetype of the meatcutting machines. conduits for connecting the machineswith one another, and one or several pipes for supplying-liquid to theseveral machines.

In-testimonv whereof I aflix my signature in presence of two witnesses.

OTTO VEXTER.

Witnesses Fem). IN CSCH, PAUL RonsY.

